The present invention is an energy-absorbing device, applicable in particular to automobile vehicle steering columns, with a view to absorbing energy in the event of an impact.
Many energy-absorbing systems or devices are known, but they are often relatively bulky and therefore not easily usable in structures having limited available volume. The dimensioning of the energy-absorbing device as well as its cost and complexity are the most frequently encountered drawbacks.
Document EP-0-252-031 describes an energy-absorbing device comprising two elements mobile in translation with respect to each other, one of the elements supporting two axes about which are rolled, respectively, two metal bands forming a spiral, one of the ends of each band being rigidly locked to an axis whereas the other end is fixed to the other element. During energy absorption, the two elements move closer to each other causing the two metal bands to unwind. When metal bands forming spirals are used, the higher the force to be reached and the longer the absorption distance of travel required, the larger the energy-absorbing device has to be.
Document GB-1.120.799 describes a steering column, comprising two telescopic parts which fit one inside the other and provided with an energy-absorbing device. The latter is made up of two systems, the first formed of a foldable piece, and the second of two metal bands, absorbing a part of the energy by bending and elongation.
Document GB-2.268.125 concerns an automobile vehicle steering column, comprising an energy-absorbing device made up of a rigid support coupled to the steering tube and having two longitudinal slots, parallel to the axis of the column. A bolt connects this support to a console in order to allow the adjustment of the steering column. This bolt is associated with a deformable band, welded to the support. This device adsorbs the energy at the time of an impact by displacement of the bolt towards the outside of the longitudinal slots, causing a displacement of the deformable strip. In this device, the absorption technique does not intervene at the time of the adjustment of the steering column, nor during the first phase of the impact.
A device adaptable to a steering column adjustable in inclination is described in U.S. Pat. No. 4,901,592. It comprises a U-shaped plate, the end of one of its branches being connected to the steering column and the other to a support fixed to the vehicle body. Energy absorption is performed by the displacement and deformation of the curved part of the U-shaped plate.